May 2017

Benefits of blood flow: Effect may facilitate Achilles healing

In the moment: Sports medicine

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By Katie Bell

Microcirculatory blood flow two weeks after Achilles tendon repair is correlated with long-term patient-reported and functional outcomes, according to research from Sweden in which blood flow in both the injured and contralateral tendons was associated with healing potential.

“The collective observations from our study support the conception that higher resting ‘flux’ [rate of blood flow] in the uninjured Achilles tendon is a reflection of tendinopathy, which is a general disease also occurring in the contralateral tendon and which is associated with inferior outcome after Achilles tendon rupture. It suggests that rehab should focus on both limbs,” said corresponding author Paul Ackermann, MD, PhD, associate professor and specialist in orthopedic surgery at Karolinska University Hospital in Stockholm.

The study analyzed nine men (mean age 36.6 years) who were part of a larger study that examined the prevalence and prevention of deep venous thrombosis after unilateral Achilles rupture. All nine participants underwent surgery within 72 hours of injury; most were “weekend warriors,” Ackermann said.

After surgical repair of the tendon, the patients underwent two weeks of postoperative rehabilitation; five were part of a group randomized to receive intermittent pneumatic calf compression beneath a weightbearing orthotic device, while four received nonweightbearing plaster cast treatment. At two weeks postsurgery, laser Doppler flowmetry was used to assess microvascular blood flow in the midportion of the Achilles tendon bilaterally, during postocclusive reactive hyperemia.

“At two weeks, all patients returned for follow-up and were mobilized with an orthosis and were instructed to start bearing their full weight. At six weeks, the brace was removed,” Ackermann said.

At three months postoperatively, patient-reported outcomes were assessed using the Achilles tendon Total Rupture Score (ATRS). At one year, the Achilles Combined Outcome Score (ACOS) was obtained by combining validated, independent, patient-reported ATRS and functional outcome (heel-rise test) measures. All nine patients were analyzed as one group.

A better ACOS outcome at one year was significantly correlated with higher maximum blood flow in the injured Achilles tendon. Additionally, a better ATRS outcome at three months was significantly correlated with an elevated ratio of maximum to resting blood flow in the uninjured Achilles tendon. The findings were epublished by the Scandinavian Journal of Medicine & Science in Sports in April.

Because physical activity influences microcirculation, the researchers looked specifically at patient characteristics that may affect physical activity (gender, age, body mass index [BMI], and smoking). Of these, age and BMI were the only variables that were significantly correlated with microcirculation.

Although the study did not assess the effects of different rehab protocols on blood flow or longer-term outcomes, “we believe that rehab can greatly influence microcirculation and thereby possibly healing,” Ackermann said. “The best effects on leg blood flow that we have found thus far is to use intermittent pneumatic compression beneath a weightbearing orthotic device.”

Karin Grävare Silbernagel, PT, ATC, PhD, an assistant professor in the Department of Physical Therapy at the University of Delaware in Newark, noted that the observed correlations in the Swedish study are likely related to the effects of weightbearing and loading during rehabilitation.

“I think blood circulation is of interest, but is probably related to activity, loading, or weightbearing status. It could be that the correlation found in the study is secondary to the two different treatments or weightbearing status and amount of weightbearing/loading that the patient has performed,” Silbernagel said. “What we know today is that tendons need mechanical loading for healing. However, we do not know how that optimal loading should look.”

However, Silbernagel said the rehab protocol she uses for patients who have had Achilles repair does include a vascular component.

“I use compression socks for all my patients to avoid swelling so the Achilles tendon has the best healing environment, which would include having good circulation,” she said.